1
|
Barbara M, Margani V, Covelli E, Filippi C, Volpini L, El-Borady OM, El-Kemary M, Elzayat S, Elfarargy HH. The Use of Nanoparticles in Otoprotection. Front Neurol 2022; 13:912647. [PMID: 35968304 PMCID: PMC9364836 DOI: 10.3389/fneur.2022.912647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/31/2022] [Indexed: 11/24/2022] Open
Abstract
The inner ear can be insulted by various noxious stimuli, including drugs (cisplatin and aminoglycosides) and over-acoustic stimulation. These stimuli damage the hair cells giving rise to progressive hearing loss. Systemic drugs have attempted protection from ototoxicity. Most of these drugs poorly reach the inner ear with consequent ineffective action on hearing. The reason for these failures resides in the poor inner ear blood supply, the presence of the blood-labyrinthine barrier, and the low permeability of the round window membrane (RWM). This article presents a review of the use of nanoparticles (NPs) in otoprotection. NPs were recently used in many fields of medicine because of their ability to deliver drugs to the target organs or cells. The studies included in the review regarded the biocompatibility of the used NPs by in vitro and in vivo experiments. In most studies, NPs proved safe without a significant decrease in cell viability or signs of ototoxicity. Many nano-techniques were used to improve the drugs' kinetics and efficiency. These techniques included encapsulation, polymerization, surface functionalization, and enhanced drug release. In such a way, it improved drug transmission through the RWM with increased and prolonged intra-cochlear drug concentrations. In all studies, the fabricated drug-NPs effectively preserved the hair cells and the functioning hearing from exposure to different ototoxic stimuli, simulating the actual clinical circumstances. Most of these studies regarded cisplatin ototoxicity due to the wide use of this drug in clinical oncology. Dexamethasone (DEX) and antioxidants represent the most used drugs in most studies. These drugs effectively prevented apoptosis and reactive oxygen species (ROS) production caused by ototoxic stimuli. These various successful experiments confirmed the biocompatibility of different NPs and made it successfully to human clinical trials.
Collapse
Affiliation(s)
- Maurizio Barbara
- Department of Neuroscience, Mental Health and Sensory Organs, Faculty of Medicine and Psychology, Sapienza University, Rome, Italy
| | - Valerio Margani
- Department of Neuroscience, Mental Health and Sensory Organs, Faculty of Medicine and Psychology, Sapienza University, Rome, Italy
| | - Edoardo Covelli
- Department of Neuroscience, Mental Health and Sensory Organs, Faculty of Medicine and Psychology, Sapienza University, Rome, Italy
| | - Chiara Filippi
- Department of Neuroscience, Mental Health and Sensory Organs, Faculty of Medicine and Psychology, Sapienza University, Rome, Italy
| | - Luigi Volpini
- Otolaryngology Department, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
| | - Ola M. El-Borady
- Institute of Nanoscience and Nanotechnology, Kafrelsheikh University, Kafr El-Shaikh, Egypt
| | - Maged El-Kemary
- Institute of Nanoscience and Nanotechnology, Kafrelsheikh University, Kafr El-Shaikh, Egypt
| | - Saad Elzayat
- Otolaryngology Department, Faculty of Medicine, Kafrelsheikh University, Kafr El-Shaikh, Egypt
| | - Haitham H. Elfarargy
- Otolaryngology Department, Faculty of Medicine, Kafrelsheikh University, Kafr El-Shaikh, Egypt
- *Correspondence: Haitham H. Elfarargy ;
| |
Collapse
|
2
|
A Perspective for Ménière’s Disease: In Silico Investigations of Dexamethasone as a Direct Modulator of AQP2. Biomolecules 2022; 12:biom12040511. [PMID: 35454100 PMCID: PMC9028334 DOI: 10.3390/biom12040511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 12/04/2022] Open
Abstract
Ménière’s disease is a chronic illness characterized by intermittent episodes of vertigo associated with fluctuating sensorineural hearing loss, tinnitus and aural pressure. This pathology strongly correlates with a dilatation of the fluid compartment of the endolymph, so-called hydrops. Dexamethasone is one of the therapeutic approaches recommended when conventional antivertigo treatments have failed. Several mechanisms of actions have been hypothesized for the mode of action of dexamethasone, such as the anti-inflammatory effect or as a regulator of inner ear water homeostasis. However, none of them have been experimentally confirmed so far. Aquaporins (AQPs) are transmembrane water channels and are hence central in the regulation of transcellular water fluxes. In the present study, we investigated the hypothesis that dexamethasone could impact water fluxes in the inner ear by targeting AQP2. We addressed this question through molecular dynamics simulations approaches and managed to demonstrate a direct interaction between AQP2 and dexamethasone and its significant impact on the channel water permeability. Through compartmentalization of sodium and potassium ions, a significant effect of Na+ upon AQP2 water permeability was highlighted as well. The molecular mechanisms involved in dexamethasone binding and in its regulatory action upon AQP2 function are described.
Collapse
|
3
|
Xu J, Yu D, Dong X, Xie X, Xu M, Guo L, Huang L, Tang Q, Gan L. GATA3 maintains the quiescent state of cochlear supporting cells by regulating p27 kip1. Sci Rep 2021; 11:15779. [PMID: 34349220 PMCID: PMC8338922 DOI: 10.1038/s41598-021-95427-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/26/2021] [Indexed: 01/22/2023] Open
Abstract
Haplo-insufficiency of the GATA3 gene causes hypoparathyroidism, sensorineural hearing loss, and renal disease (HDR) syndrome. Previous studies have shown that Gata3 is required for the development of the prosensory domain and spiral ganglion neurons (SGNs) of the mouse cochlea during embryogenesis. However, its role in supporting cells (SCs) after cell fate specification is largely unknown. In this study, we used tamoxifen-inducible Sox2CreERT2 mice to delete Gata3 in SCs of the neonatal mouse cochlea and showed that loss of Gata3 resulted in the proliferation of SCs, including the inner pillar cells (IPCs), inner border cells (IBCs), and lateral greater epithelium ridge (GER). In addition, loss of Gata3 resulted in the down-regulation of p27kip1, a cell cycle inhibitor, in the SCs of Gata3-CKO neonatal cochleae. Chromatin immunoprecipitation analysis revealed that GATA3 directly binds to p27kip1 promoter and could maintain the quiescent state of cochlear SCs by regulating p27kip1 expression. Furthermore, RNA-seq analysis revealed that loss of Gata3 function resulted in the change in the expression of genes essential for the development and function of cochlear SCs, including Tectb, Cyp26b1, Slitrk6, Ano1, and Aqp4.
Collapse
Affiliation(s)
- Jiadong Xu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Dongliang Yu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, Zhejiang, China
| | - Xuhui Dong
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Xiaoling Xie
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Mei Xu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Luming Guo
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Liang Huang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Qi Tang
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lin Gan
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA.
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
| |
Collapse
|
4
|
Histology of the Cochlear Outer Sulcus Cells in Normal Human Ears, Presbycusis, and Menière's Disease. Otol Neurotol 2020; 41:e507-e515. [PMID: 32176147 DOI: 10.1097/mao.0000000000002535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Outer sulcus cell features and distribution are hypothesized to differ throughout regions of the human cochlea and between diseased and normal specimens. BACKGROUND Outer sulcus cells play a role in inner ear fluid homeostasis. However, their anatomy and distribution in the human are not well described. METHODS Temporal bone specimens with normal hearing (n = 10), Menière's disease (n = 10), presbycusis with flat audiograms (n = 4), and presbycusis with sloping audiograms (n = 5) were examined by light microscopy. Outer sulcus cells were assessed quantitatively and qualitatively in each cochlear turn. One specimen was stained for tubulin immunofluorescence and imaged using confocal microscopy. RESULTS Outer sulcus cells interface with endolymph throughout the cochlea, with greatest contact in the apical turn. Mean outer sulcus cell counts in the upper apical turn (8.82) were generally smaller (all p < 0.05) than those of the upper basal (17.71), lower middle (18.99) upper middle (18.23), and lower apical (16.42) turns. Mean outer sulcus cell counts were higher (p < 0.05) in normal controls (20.1) than in diseased specimens (15.29). There was a significant correlation between mean cell counts and tonotopically expected hearing thresholds in the upper basal (r = -0.662, p = 0.0001), lower middle (r = -0.565, p = 0.0017), and upper middle (r = -0.507, p = 0.0136) regions. Other differences in cell morphology, distribution, or relationship with Claudius cells were not appreciated between normal and diseased specimens. Menière's specimens had no apparent unique features in the cochlear apex. Immunofluorescence staining demonstrated outer sulcus cells extending into the spiral ligament in bundles forming tapering processes which differed between the cochlear turns in morphology. CONCLUSION Outer sulcus cells vary throughout the cochlear turns and correlate with hearing status, but not in a manner specific to the underlying diagnoses of Menière's disease or presbycusis.
Collapse
|
5
|
Dong SH, Kim SS, Kim SH, Yeo SG. Expression of aquaporins in inner ear disease. Laryngoscope 2019; 130:1532-1539. [PMID: 31593306 DOI: 10.1002/lary.28334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 12/22/2022]
Abstract
The inner ear is responsible for hearing and balance and consists of a membranous labyrinth within a bony labyrinth. The balance structure is divided into the otolith organ that recognizes linear acceleration and the semicircular canal that is responsible for rotational movement. The cochlea is the hearing organ. The external and middle ear are covered with skin and mucosa, respectively, and the space is filled with air, whereas the inner ear is composed of endolymph and perilymph. The inner ear is a fluid-filled sensory organ composed of hair cells with cilia on the upper part of the cells that convert changes in sound energy and balance into electric energy through the hair cells to transmit signals to the auditory nerve through synapses. Aquaporins (AQPs) are a family of transmembrane proteins present in all species that can be roughly divided into three subfamilies according to structure and function: 1) classical AQP, 2) aquaglyceroporin, and 3) superaquaporin. Currently, the subfamily of mammalian species is known to include 13 AQP members (AQP0-AQP12). AQPs have a variety of functions depending on their structure and are related to inner ear diseases such as Meniere's disease, sensorineural hearing loss, and presbycusis. Additional studies on the relationship between the inner ear and AQPs may be helpful in the diagnosis and treatment of inner ear disease. Laryngoscope, 130:1532-1539, 2020.
Collapse
Affiliation(s)
- Sung Hwa Dong
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sung Su Kim
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sang Hoon Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea.,Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| |
Collapse
|
6
|
Mittal R, Pena SA, Zhu A, Eshraghi N, Fesharaki A, Horesh EJ, Mittal J, Eshraghi AA. Nanoparticle-based drug delivery in the inner ear: current challenges, limitations and opportunities. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:1312-1320. [PMID: 30987439 DOI: 10.1080/21691401.2019.1573182] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hearing loss is the most common neurosensory impairment worldwide. While conductive hearing loss can be managed by surgery, the management of sensorineural hearing loss (SNHL), related to the damage of sensory cells of the inner ear is more challenging to manage medically. Many causes of SNHL such as sudden idiopathic SNHL, Meniere's disease, noise-induced hearing loss, autoimmune hearing loss or hearing loss from exposure to ototoxic substances can benefit from delivery of otoprotective drugs to the inner ear. However, systemic drug delivery through oral, intravenous and intramuscular methods leads to undesirable side effects due to the inner ear's limited blood supply and the relatively poor penetration of the blood-inner ear barrier (BLB). Therefore, there has been an increased interest for the targeted drug delivery to the inner ear using nanoparticles. Drug delivery through nanoparticles offers several advantages including drug stabilization for controlled release and surface modification for specific targeting. Understanding the biocompatibility of nanoparticles with cochlea and developing novel non-invasive delivery methods will promote the translation of nanoparticle-mediated drug delivery for auditory disorders from bench to bedside.
Collapse
Affiliation(s)
- Rahul Mittal
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Stefanie A Pena
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Angela Zhu
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Nicolas Eshraghi
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Arian Fesharaki
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Elijah J Horesh
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Jeenu Mittal
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA
| | - Adrien A Eshraghi
- a Department of Otolaryngology, Hearing Research Laboratory , University of Miami Miller School of Medicine , Miami , FL, USA.,b Department of Neurological Surgery , University of Miami Miller School of Medicine , Miami , FL, USA
| |
Collapse
|
7
|
Kim J, Xia A, Grillet N, Applegate BE, Oghalai JS. Osmotic stabilization prevents cochlear synaptopathy after blast trauma. Proc Natl Acad Sci U S A 2018; 115:E4853-E4860. [PMID: 29735658 PMCID: PMC6003510 DOI: 10.1073/pnas.1720121115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Traumatic noise causes hearing loss by damaging sensory hair cells and their auditory synapses. There are no treatments. Here, we investigated mice exposed to a blast wave approximating a roadside bomb. In vivo cochlear imaging revealed an increase in the volume of endolymph, the fluid within scala media, termed endolymphatic hydrops. Endolymphatic hydrops, hair cell loss, and cochlear synaptopathy were initiated by trauma to the mechanosensitive hair cell stereocilia and were K+-dependent. Increasing the osmolality of the adjacent perilymph treated endolymphatic hydrops and prevented synaptopathy, but did not prevent hair cell loss. Conversely, inducing endolymphatic hydrops in control mice by lowering perilymph osmolality caused cochlear synaptopathy that was glutamate-dependent, but did not cause hair cell loss. Thus, endolymphatic hydrops is a surrogate marker for synaptic bouton swelling after hair cells release excitotoxic levels of glutamate. Because osmotic stabilization prevents neural damage, it is a potential treatment to reduce hearing loss after noise exposure.
Collapse
Affiliation(s)
- Jinkyung Kim
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Nicolas Grillet
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Brian E Applegate
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033
| |
Collapse
|
8
|
Asmar MH, Gaboury L, Saliba I. Ménière’s Disease Pathophysiology: Endolymphatic Sac Immunohistochemical Study of Aquaporin-2, V2R Vasopressin Receptor, NKCC2, and TRPV4. Otolaryngol Head Neck Surg 2018; 158:721-728. [DOI: 10.1177/0194599818756829] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Objectives Endolymphatic sac (ELS) pathophysiology in Ménière’s disease (MD) remains poorly understood. We identified from the literature a group of proteins expressed on the ELS and involved in endolymph volume regulation: aquaporin-2 (AQP2), vasopressin receptor V2R, sodium potassium chloride cotransporter 2 (NKCC2), and transient receptor potential cation channel V4 (TRPV4). Our objective was to determine whether their ELS expression was altered in MD, to better understand the pathophysiology of endolymphatic hydrops. Study Design Prospective case-control study. Setting Tertiary care center. Subjects Twenty-four patients with definite MD undergoing endolymphatic duct blockage surgery were recruited, as well as 23 controls with no history of MD undergoing surgery for vestibular schwannoma (VS). Methods ELS biopsies and blood samples for plasma arginine vasopressin (AVP) were obtained. Immunohistochemistry for AQP2, V2R, NKCC2, and TRPV4 was performed. Slides were scanned digitally for highly sensitive pixel density analysis by specialized software (VIS; Visiopharm). Results Global scores generated by the software represent total and relative protein expression density of 3 staining intensity levels, exclusively on ELS epithelium. AQP2 expression density was significantly elevated in MD compared to VS ( P = .003). There was no significant difference in plasma AVP, V2R, NKCC2, and TRPV4 expression. Conclusion This original study evaluates simultaneous in situ expression of AQP2, V2R, NKCC2, and TRPV4 on the human ELS in MD, with a control group. Our results show only AQP2 upregulation on the ELS of patients with MD. We suggest a constitutively increased expression of AQP2 in MD, independent of its regulatory axis (AVP-V2R). Acquired regulator sequence mutations could support this model.
Collapse
Affiliation(s)
- Marc-Henri Asmar
- University of Montreal Hospital Centre Research Centre (CRCHUM), Montreal, QC, Canada
| | - Louis Gaboury
- University of Montreal Hospital Centre Research Centre (CRCHUM), Montreal, QC, Canada
- Department of Pathology and Cell Biology, University of Montreal Hospital Centre (CHUM), Montreal, QC, Canada
| | - Issam Saliba
- University of Montreal Hospital Centre Research Centre (CRCHUM), Montreal, QC, Canada
- Division of Otolaryngology–Head & Neck Surgery, University of Montreal Hospital Centre (CHUM), Montreal, QC, Canada
| |
Collapse
|
9
|
Chang YL, Jian KR, Lin CS, Wang HW, Liu SC. Dexamethasone attenuates methacholine-mediated aquaporin 5 downregulation in human nasal epithelial cells via suppression of NF-κB activation. Int Forum Allergy Rhinol 2017; 8:64-71. [PMID: 29083535 DOI: 10.1002/alr.22035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/05/2017] [Accepted: 10/08/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND Cholinergic stimulation plays a major role in inflammatory airway diseases. However, its role in airway surface liquid homeostasis and aquaporin 5 (AQP5) regulation remains unclear. In this study we sought to determine the effects of methacholine and dexamethasone on AQP5 expression in human nasal epithelial cells (HNEpC). METHODS HNEpC were cultured with methacholine or dexamethasone at 4 concentrations in vitro. The subcellular distribution of AQP5 was explored using immunocytochemistry. The pharmacologic effects of methacholine and dexamethasone on the expression of the phosphorylation of cyclic adenosine monophosphate-responsive element binding protein (p-CREB), AQP5, and nuclear factor-kappaB (NF-κB) were examined using Western blotting. RESULTS AQP5 was found to be located in cell membrane and cytoplasm and present in every group without a statistically significant difference. Methacholine inhibited expression of AQP5 and p-CREB in HNEpC, whereas dexamethasone increased these protein levels dose-dependently in a statistically significant manner. In turn, HNEpC treated with methacholine and dexamethasone showed the same trends as those intervened separately with these 2 drugs. Moreover, dexamethasone had the ability to reverse the inhibitory effect of methacholine. Western blotting revealed that, after incubation with 10-4 mol/L methacholine, NF-κB increased significantly, by 186.67%, compared with the untreated control group. Again, such an increase could be significantly reversed after dexamethasone treatment. CONCLUSION NF-κB activation is important for inhibition of p-CREB/AQP5 expression after methacholine intervention, and dexamethasone adjusts it to the opposite side. This observation could provide additional insight into the anti-inflammatory effects of glucocorticoids that contribute to maintaining airway surface liquid and mucosal defense.
Collapse
Affiliation(s)
- Yung-Lung Chang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Kai Ren Jian
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chun-Shu Lin
- Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Hsing-Won Wang
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center.,Department of Otolaryngology-Head and Neck Surgery, Shuang Ho Hospital, Taipei, Taiwan, Republic of China
| | - Shao-Cheng Liu
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center
| |
Collapse
|
10
|
Wangemann P, Marcus DC. Ion and Fluid Homeostasis in the Cochlea. UNDERSTANDING THE COCHLEA 2017. [DOI: 10.1007/978-3-319-52073-5_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
11
|
Ion transport its regulation in the endolymphatic sac: suggestions for clinical aspects of Meniere's disease. Eur Arch Otorhinolaryngol 2016; 274:1813-1820. [PMID: 27804084 PMCID: PMC5340852 DOI: 10.1007/s00405-016-4362-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 10/26/2016] [Indexed: 01/22/2023]
Abstract
Ion transport and its regulation in the endolymphatic sac (ES) are reviewed on the basis of recent lines of evidence. The morphological and physiological findings demonstrate that epithelial cells in the intermediate portion of the ES are more functional in ion transport than those in the other portions. Several ion channels, ion transporters, ion exchangers, and so on have been reported to be present in epithelial cells of ES intermediate portion. An imaging study has shown that mitochondria-rich cells in the ES intermediate portion have a higher activity of Na+, K+-ATPase and a higher Na+ permeability than other type of cells, implying that molecules related to Na+ transport, such as epithelial sodium channel (ENaC), Na+–K+–2Cl− cotransporter 2 (NKCC2) and thiazide-sensitive Na+–Cl− cotransporter (NCC), may be present in mitochondria-rich cells. Accumulated lines of evidence suggests that Na+ transport is most important in the ES, and that mitochondria-rich cells play crucial roles in Na+ transport in the ES. Several lines of evidence support the hypothesis that aldosterone may regulate Na+ transport in ES, resulting in endolymph volume regulation. The presence of molecules related to acid/base transport, such as H+-ATPase, Na+–H+ exchanger (NHE), pendrin (SLC26A4), Cl−–HCO3− exchanger (SLC4A2), and carbonic anhydrase in ES epithelial cells, suggests that acid/base transport is another important one in the ES. Recent basic and clinical studies suggest that aldosterone may be involved in the effect of salt-reduced diet treatment in Meniere’s disease.
Collapse
|
12
|
Increased aquaporin 1 and 5 membrane expression in the lens epithelium of cataract patients. Biochim Biophys Acta Mol Basis Dis 2016; 1862:2015-21. [DOI: 10.1016/j.bbadis.2016.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/04/2016] [Accepted: 08/02/2016] [Indexed: 11/20/2022]
|
13
|
Gleiser C, Wagner A, Fallier-Becker P, Wolburg H, Hirt B, Mack AF. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs-A Comparative Perspective. Int J Mol Sci 2016; 17:E1411. [PMID: 27571065 PMCID: PMC5037691 DOI: 10.3390/ijms17091411] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 01/28/2023] Open
Abstract
The main water channel of the brain, aquaporin-4 (AQP4), is one of the classical water-specific aquaporins. It is expressed in many epithelial tissues in the basolateral membrane domain. It is present in the membranes of supporting cells in most sensory organs in a specifically adapted pattern: in the supporting cells of the olfactory mucosa, AQP4 occurs along the basolateral aspects, in mammalian retinal Müller cells it is highly polarized. In the cochlear epithelium of the inner ear, it is expressed basolaterally in some cells but strictly basally in others. Within the central nervous system, aquaporin-4 (AQP4) is expressed by cells of the astroglial family, more specifically, by astrocytes and ependymal cells. In the mammalian brain, AQP4 is located in high density in the membranes of astrocytic endfeet facing the pial surface and surrounding blood vessels. At these locations, AQP4 plays a role in the maintenance of ionic homeostasis and volume regulation. This highly polarized expression has not been observed in the brain of fish where astroglial cells have long processes and occur mostly as radial glial cells. In the brain of the zebrafish, AQP4 immunoreactivity is found along the radial extent of astroglial cells. This suggests that the polarized expression of AQP4 was not present at all stages of evolution. Thus, a polarized expression of AQP4 as part of a control mechanism for a stable ionic environment and water balanced occurred at several locations in supporting and glial cells during evolution. This initially basolateral membrane localization of AQP4 is shifted to highly polarized expression in astrocytic endfeet in the mammalian brain and serves as a part of the neurovascular unit to efficiently maintain homeostasis.
Collapse
Affiliation(s)
- Corinna Gleiser
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Andreas Wagner
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, Eberhard Karls Universität Tübingen, 72076 Tubingen, Germany.
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, Eberhard Karls Universität Tübingen, 72076 Tubingen, Germany.
| | - Bernhard Hirt
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Andreas F Mack
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| |
Collapse
|
14
|
Brown DJ, Pastras CJ, Curthoys IS, Southwell CS, Van Roon L. Endolymph movement visualized with light sheet fluorescence microscopy in an acute hydrops model. Hear Res 2016; 339:112-24. [PMID: 27377233 DOI: 10.1016/j.heares.2016.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/30/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
Abstract
There are a variety of techniques available to investigate endolymph dynamics, primarily seeking to understand the cause of endolymphatic hydrops. Here we have taken the novel approach of injecting, via a glass micropipette, fluorescein isothiocyanate-dextran (FITC-dex) and artificial endolymph into scala media of anaesthetized guinea pigs, with subsequent imaging of the inner ear using Light Sheet Fluorescence Microscopy (LSFM) as a means to obtain highly resolved 3D visualization of fluid movements. Our results demonstrate endolymph movement into the utricle, semicircular canals and endolymphatic duct and sac when more than 2.5 μl of fluid had been injected into scala media, with no apparent movement of fluid into the perilymphatic compartments. There was no movement of endolymph into these compartments when less than 2.5 μl was injected. The remarkable uptake of the FITC-dex into the endolymphatic duct, including an absorption into the periductal channels surrounding the endolymphatic duct, highlights the functional role this structure plays in endolymph volume regulation.
Collapse
Affiliation(s)
- Daniel J Brown
- Sydney Medical School, The University of Sydney, Sydney, NSW, 2050, Australia.
| | | | - Ian S Curthoys
- Vestibular Research Laboratory, The University of Sydney, School of Psychology, Sydney, NSW, 2050, Australia
| | | | - Lieke Van Roon
- University of Utrecht, Faculty Nature and Technique, Inst. for Life Sciences and Chemistry, Utrecht, 3508 AD, The Netherlands
| |
Collapse
|
15
|
Bragiel AM, Wang D, Pieczonka TD, Shono M, Ishikawa Y. Mechanisms Underlying Activation of α₁-Adrenergic Receptor-Induced Trafficking of AQP5 in Rat Parotid Acinar Cells under Isotonic or Hypotonic Conditions. Int J Mol Sci 2016; 17:ijms17071022. [PMID: 27367668 PMCID: PMC4964398 DOI: 10.3390/ijms17071022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/15/2016] [Accepted: 06/23/2016] [Indexed: 11/18/2022] Open
Abstract
Defective cellular trafficking of aquaporin-5 (AQP5) to the apical plasma membrane (APM) in salivary glands is associated with the loss of salivary fluid secretion. To examine mechanisms of α1-adrenoceptor (AR)-induced trafficking of AQP5, immunoconfocal microscopy and Western blot analysis were used to analyze AQP5 localization in parotid tissues stimulated with phenylephrine under different osmolality. Phenylephrine-induced trafficking of AQP5 to the APM and lateral plasma membrane (LPM) was mediated via the α1A-AR subtype, but not the α1B- and α1D-AR subtypes. Phenylephrine-induced trafficking of AQP5 was inhibited by ODQ and KT5823, inhibitors of nitric oxide (NO)-stimulated guanylcyclase (GC) and protein kinase (PK) G, respectively, indicating the involvement of the NO/ soluble (c) GC/PKG signaling pathway. Under isotonic conditions, phenylephrine-induced trafficking was inhibited by La3+, implying the participation of store-operated Ca2+ channel. Under hypotonic conditions, phenylephrine-induced trafficking of AQP5 to the APM was higher than that under isotonic conditions. Under non-stimulated conditions, hypotonicity-induced trafficking of AQP5 to the APM was inhibited by ruthenium red and La3+, suggesting the involvement of extracellular Ca2+ entry. Thus, α1A-AR activation induced the trafficking of AQP5 to the APM and LPM via the Ca2+/ cyclic guanosine monophosphate (cGMP)/PKG signaling pathway, which is associated with store-operated Ca2+ entry.
Collapse
Affiliation(s)
- Aneta M Bragiel
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan.
| | - Di Wang
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan.
| | - Tomasz D Pieczonka
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan.
| | - Masayuki Shono
- Support Center for Advanced Medical Sciences, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan.
| | - Yasuko Ishikawa
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan.
| |
Collapse
|
16
|
Vincent PF, Bouleau Y, Petit C, Dulon D. A synaptic F-actin network controls otoferlin-dependent exocytosis in auditory inner hair cells. eLife 2015; 4. [PMID: 26568308 PMCID: PMC4714970 DOI: 10.7554/elife.10988] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/12/2015] [Indexed: 12/04/2022] Open
Abstract
We show that a cage-shaped F-actin network is essential for maintaining a tight spatial organization of Cav1.3 Ca2+ channels at the synaptic ribbons of auditory inner hair cells. This F-actin network is also found to provide mechanosensitivity to the Cav1.3 channels when varying intracellular hydrostatic pressure. Furthermore, this F-actin mesh network attached to the synaptic ribbons directly influences the efficiency of otoferlin-dependent exocytosis and its sensitivity to intracellular hydrostatic pressure, independently of its action on the Cav1.3 channels. We propose a new mechanistic model for vesicle exocytosis in auditory hair cells where the rate of vesicle recruitment to the ribbons is directly controlled by a synaptic F-actin network and changes in intracellular hydrostatic pressure. DOI:http://dx.doi.org/10.7554/eLife.10988.001 To hear a sound, the pressure produced by sound waves must be converted into an electrical nerve signal. The cells inside the ear that perform this transformation are called hair cells, which are so named because they have hundreds of hair-like structures on their upper surface. Pressure from sound waves causes movements in the inner ear that bend these ‘hairs’. This causes the hair cells to release chemical signals to neighboring nerve cell terminals that ultimately transmit information about the sound to the brain. The chemical signals are stored inside the hair cells in bubble-like compartments called vesicles. To release the chemicals from the cell, the vesicles merge with the membrane that surrounds the hair cell. Most cells that communicate in this way are limited in how long they can transmit such messages. However, hair cells can continuously fuse vesicles to the membrane even when a sound lasts for a long time. This suggests that the hair cells have a different way of producing vesicles and getting them to the membrane than other cell types. Inside the hair cells, vesicles are stored in regions called active zones. Each active zone contains a “ribbon” (attached to which are hundreds of vesicles) and also ion channels that allow calcium ions to flow into the cell. (An increase in calcium ion concentration inside the cell is necessary for the vesicle to fuse with the cell membrane and so release its chemical content). Now, Vincent et al. show that in hair cells, a cage-like network made from a protein called actin surrounds each active zone. This network helps to position the calcium ion channels. Treating the hair cells with a compound that disorganized the actin networks speed up the process of vesicle movement, which suggests that the actin network also controls the rate at which vesicles reach the membrane. Next, it will be important to identify how the actin network interacts with other molecules that help vesicles to release their contents; in particular a protein called otoferlin, which is thought to act as a calcium ion sensor. DOI:http://dx.doi.org/10.7554/eLife.10988.002
Collapse
Affiliation(s)
- Philippe Fy Vincent
- Bordeaux Neurocampus, Equipe Neurophysiologie de la Synapse Auditive, Université de Bordeaux, Bordeaux, France
| | - Yohan Bouleau
- Bordeaux Neurocampus, Equipe Neurophysiologie de la Synapse Auditive, Université de Bordeaux, Bordeaux, France
| | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, Paris, France.,UMRS 1120, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France.,Sorbonne Universités, UPMC Université Paris, Paris, France.,Syndrome de Usher et Autres Atteintes Rétino-Cochléaires, Institut de la Vision, Paris, France.,Collège de France, Paris, France
| | - Didier Dulon
- Bordeaux Neurocampus, Equipe Neurophysiologie de la Synapse Auditive, Université de Bordeaux, Bordeaux, France.,UMRS 1120, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
| |
Collapse
|